Low cost hardened fiber optic connection system

ABSTRACT

The present disclosure relates to a ruggedized/hardened fiber optic connection system designed to reduce cost. In one example, selected features of a fiber optic adapter are integrated with a wall ( 24 ) of an enclosure ( 22 ). The adapter comprises a sleeve port ( 26 ) into which an optical adapter subassembly is inserted. The subassembly comprises a sleeve part ( 44 ) which is inserted into the sleeve, a ferrule alignment sleeve ( 48 ) which is inserted into the sleeve part, a ferrule ( 55 ) with hub which is inserted into the alignment sleeve, and fixing clip ( 46 ) securing the ferrule with hub into the alignment sleeve and the sleeve part.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of U.S. patent application Ser. No.15/564,152, filed on Oct. 3, 2017, now U.S. Pat. No. 10,288,820, whichis a National Stage Application of PCT/EP2016/057293, filed on Apr. 3,2016, which claims the benefit of U.S. Patent Application Ser. No.62/142,836, filed on Apr. 3, 2015, the disclosures of which areincorporated herein by reference in their entireties. To the extentappropriate, a claim of priority is made to each of the above disclosedapplications.

TECHNICAL FIELD

The present disclosure relates generally to optical fiber communicationsystems. More particularly, the present disclosure relates to fiberoptic connectors and fiber optic connection systems.

BACKGROUND

Fiber optic communication systems are becoming prevalent in part becauseservice providers want to deliver high bandwidth communicationcapabilities (e.g., data and voice) to customers. Fiber opticcommunication systems employ a network of fiber optic cables to transmitlarge volumes of data and voice signals over relatively long distances.Optical fiber connectors are an important part of most fiber opticcommunication systems. Fiber optic connectors allow two optical fibersto be quickly optically connected together without requiring a splice,and also allow such optical fibers to be easily disconnected from oneanother. Fiber optic connectors can be used to optically interconnecttwo lengths of optical fiber. Fiber optic connectors can also be used tointerconnect lengths of optical fiber to passive and active equipment.

A typical fiber optic connector includes a ferrule assembly supported ata distal end of a connector housing. A spring is used to bias theferrule assembly in a distal direction relative to the connectorhousing. The ferrule functions to support an end portion of at least oneoptical fiber (in the case of a multi-fiber ferrule, the ends ofmultiple fibers are supported). The ferrule has a distal end face atwhich a polished end of the optical fiber is located. When two fiberoptic connectors are interconnected, the distal end faces of theferrules abut or are in close proximity to one another and the ferrulesare forced proximally relative to their respective connector housingsagainst the bias of their respective springs. Ideally, the opticalfibers of two connected fiber optic connectors are coaxially alignedsuch that the end faces of the optical fibers directly oppose oneanother. In this way, an optical signal can be transmitted from opticalfiber to optical fiber through the aligned end faces of the opticalfibers. For many fiber optic connector styles, alignment between twofiber optic connectors is provided through the use of an intermediatefiber optic adapter (see U.S. Pat. No. 5,317,663, which is herebyincorporated herein by reference) having a sleeve that receives andaligns the respective ferrules supporting the optical fibers desired tobe optically coupled together.

Ruggedized (i.e., hardened) fiber optic connection systems include fiberoptic connectors and fiber optic adapters suitable for outsideenvironmental use. These types of systems are typically environmentallysealed and include robust fastening arrangements suitable forwithstanding relatively large pull loading and side loading. Exampleruggedized fiber optic connection systems are disclosed by U.S. Pat.Nos. 7,467,896; 7,744,288 and 8,556,520. Improvements are needed in theareas of assembly and cost.

SUMMARY

One aspect of the present disclosure relates to a telecommunicationsdevice including an enclosure having an enclosure wall and a sleeveunitarily integrated with the enclosure wall. The sleeve defines aconnector port that extends through the enclosure wall. The sleeveincludes a connector fastening structure adjacent an outer end of thesleeve. The connector fastening structure is configured to mate with acorresponding fastening structure of an exterior hardened connector tosecure the exterior hardened connector within the connector port. Asubassembly mounts within the enclosure at an inner end of the sleeve.The subassembly includes a housing including a front housing piece thatfastens to the inner end of the sleeve. The subassembly also includes aferrule alignment sleeve that mounts within the front housing piece. Thesubassembly further includes a ferrule assembly including a ferrule anda ferrule hub mounted at a rear end of the ferrule. The ferrule has afront end portion that fits within the ferrule alignment sleeve. Theferrule supports an optical fiber that extends through the ferrule in arear-to-front orientation. The subassembly further includes a rearhousing piece that attaches to a rear end of the front housing andcaptures the ferrule assembly within the front housing piece.

Another aspect of the present disclosure relates to a telecommunicationsdevice including a connector port defining structure having an outer endand an inner end. The connector port defining structure defines aconnector port configured for receiving a hardened fiber optic connectorat the outer end of the connector port defining structure. The connectorport defining structure includes a connector fastening structureadjacent to the outer end. The connector fastening structure isconfigured to mate with a corresponding fastening structure of thehardened fiber optic connector when the hardened fiber optic connectoris secured within the connector port. The telecommunications device alsoincludes a subassembly that mounts at the inner end of the connectorport defining structure. The subassembly includes a housing having afront housing piece that fastens to the inner end of the connector portdefining structure. The subassembly also includes a ferrule alignmentsleeve that mounts within the front housing piece. The subassemblyfurther includes a ferrule assembly including a single-fiber ferrule anda ferrule hub mounted at a rear end of the ferrule. The ferrule has afront end portion that fits within the ferrule alignment sleeve. Thesubassembly further includes a rear housing piece that attaches to arear end of the front housing and captures the ferrule subassemblywithin the front housing piece. The front housing piece defines aninternal transverse cross-sectional shape that mates with an outertransverse cross-sectional shape of the ferrule hub to prevent relativerotation between the ferrule assembly and the front housing piece whenthe internal and outer transverse cross-sectional shapes are mated.

A variety of additional aspects will be set forth in the descriptionthat follows. The aspects relate to individual features and tocombinations of features. It is to be understood that both the foregoinggeneral description and the following detailed description are exemplaryand explanatory only and are not restrictive of the broad inventiveconcepts upon which the embodiments disclosed herein are based.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an enclosure in accordance with the principles of thepresent disclosure;

FIG. 2 is a cross-sectional view through the enclosure of FIG. 1;

FIG. 2A is an enlarged, detailed view of a portion of FIG. 2;

FIG. 3 depicts an interior side of an end plate of the enclosure of FIG.1;

FIG. 4 is an exploded view of a subassembly that mounts within an innerend of a sleeve integrated with the end plate of the enclosure of FIG.1;

FIG. 5 is another exploded view of the subassembly of FIG. 4;

FIG. 6 depicts a hardened connector configured to mate with the outerend of the sleeve integrated into the end plate of FIGS. 1 and 2;

FIG. 7 depicts a connector port defining structure configured to bemounted within an opening of an enclosure, the connector port definingstructure has an inner end adapted to receive and mechanicallyinterconnect with the subassembly of FIG. 3;

FIG. 8 is a cross-sectional view of the subassembly of FIG. 3 mountedwithin the inner end of the connector port defining structure of FIG. 7;and

FIG. 9 is an end view of an example ferrule showing an example fibercore offset in exaggerated form.

DETAILED DESCRIPTION

Aspects of the present disclosure relate to ruggedized/hardened fiberoptic connection systems designed to reduce cost. In certain examples,selected fiber optic adapter features are integrated into and madeunitary with a wall of an enclosure so as to reduce the number of partsand thereby reduce costs. In certain examples, ruggedized connectorcoupling structures such as internal threads, external threads, bayonetslots, bayonet posts or other structures can be provided on a portsleeve integrated with a wall of an enclosure.

Another aspect of the present disclosure relates to a subassembly thatintegrates features of a fiber optic connector and features of a fiberoptic adapter into one subassembly. From one perspective, thesubassembly can be considered as a fiber optic connector having fiberoptic adapter functionality integrated therein. From anotherperspective, the subassembly can be viewed as a fiber optic adapterhaving fiber optic connector functionality integrated therein. Thesubassembly is configured to require a reduced number of parts ascompared to systems having a separate fiber optic adapter thatinterconnects two separate fiber optic connectors that are each intendedto be easily be inserted into and removed from the fiber optic adapter(e.g., SC connectors, LC connectors, DLX™ connectors sold by TEConnectivity, OptiTap™ connectors sold by Corning Cable Systems, etc.)By integrating features of a fiber optic connector and a fiber opticadapter into one subassembly, the total number of parts can be reducedthereby facilitating assembly operations and reducing cost.

FIGS. 1-3 illustrate a telecommunications device 20 in accordance withthe principles of the present disclosure. The telecommunications device20 includes an enclosure 22 that in certain examples is environmentallysealed. The enclosure 22 includes an enclosure wall 24 and at least onesleeve 26 unitarily integrated with the enclosure wall 24. In thedepicted example, a plurality of the sleeves 26 are unitarily integratedwith the enclosure wall 24. The sleeves 26 define connector ports 28that extend through the enclosure wall 24 from an exterior of theenclosure 22 to an interior of the enclosure 22. The sleeves 26 includeconnector fastening structures 30 positioned adjacent to outer ends 32of the sleeves 26. The connector fastening structures 30 are configuredto mate with corresponding fastening structures 34 of exterior hardenedconnectors 36 (see FIG. 6) to secure the hardened connectors 36 withinthe connector ports 28. The sleeves 26 also include inner ends 38positioned inside the enclosure 22.

Referring still to FIGS. 1-3, the telecommunications device 20 alsoincludes subassemblies 40 that mount within the enclosure 22 at theinner ends 38 of the sleeves 26. As best shown at FIGS. 3-5, thesubassemblies 40 each include a housing 42 including a front housingpiece 44 and a rear housing piece 46. The subassembly 40 also includes aferrule alignment sleeve 48 and a ferrule assembly 50 that mount withinthe front housing piece 42. The ferrule assembly 50 includes a ferrule52 and a ferrule hub 54 mounted at a rear end of the ferrule 52. Incertain examples, the ferrule 52 is a single-fiber ferrule having agenerally cylindrical front end portion 55 configured to fit within theferrule alignment sleeve 48. The subassembly 40 is assembled by loadingthe ferrule alignment sleeve 48 and the ferrule assembly 50 into thefront piece 44 through a rear end 56 of the front piece, and thenfastening the rear housing piece 46 to the rear end 56 of the fronthousing piece 44 thereby capturing the ferrule assembly 50 and theferrule alignment sleeve 48 within the interior of the front housingpiece 44. The ferrule 52 can support an optical fiber 58 (see FIG. 2)that extends through the ferrule 52 in a rear-to-front orientation.

In certain examples, the enclosure 22 can include an environmentallysealed outer housing configured for allowing the enclosure to be usedfor outdoor applications. In certain examples, the enclosure 22 canfunction as a drop terminal (i.e., a multi service terminal) thatincludes drop ports for providing optical connections to subscriberlocations through the use of drop cables. It will be appreciated thatthe drop cables can be terminated with connectors (e.g., such as theexterior hardened connector 36) which are adapted to be received withinthe connector ports 28. As shown at FIG. 1, the housing of the enclosure22 can include an end wall 60 and a removable cover structure such as adome 62. An environmental seal 64 (e.g., a gasket such as an O-ring orother type of sealing structure as shown at FIG. 2) can be providedbetween the end wall 60 and the dome 62. As shown at FIG. 2, an inputcable 66 can be routed into the interior of the enclosure 22. Within theenclosure 22, optical fibers 58 of the input cable 66 can be broken outand routed to the subassemblies 40. In certain examples, end portions ofthe optical fibers 58 are supported within the ferrules 52 of thesubassemblies 40. By inserting the connectorized end of a drop cableinto one of the connector ports 28, an optical fiber of the drop cableis optically connected to a corresponding one of the optical fibers 58.In this way, the telecommunications device 20 can be used to assist inextending and expanding fiber optic networks by providing readilyaccessible connectors ports in the field for optically connecting fiberoptic distribution cables such as the input cables 66 to subscriberlocations through the use of drop cables.

As described above, the sleeves 26 are unitarily integrated with theenclosure wall 24. The enclosure wall 24 can be any wall of theenclosure whether it is the end wall 60 or the wall forming the dome 62.By open “unitarily integrated”, it is meant that the sleeves 26 areconnected to the enclosure wall 24 at a seamless connection. In oneexample, the enclosure wall 24 and the sleeves 26 are part of aone-piece molded structure made of a material such as plastic.

Referring to FIG. 2, each of the sleeves 26 includes an outer sleeveportion 70 and an interior sleeve portion 72. The outer sleeve portion70 is unitarily formed with the enclosure wall 24 and projects outwardlyfrom the enclosure wall 24. The interior sleeve portion 72 is unitarilyformed with the enclosure wall 24 and projects inwardly from theenclosure wall. The outer sleeve portion 70 includes the connectorfastening structure 30 configured to interface with the fasteningstructure 34 of the hardened connector 36. In the depicted example, theconnector fastening structure 30 includes internal threads definedwithin the outer sleeve portion 70, and the fastening structure 34 ofthe hardened connector 36 includes outer threads provided on a nut ofthe hardened fastener 36. In other examples, the connector fasteningstructure can include outer threads defined about the exterior of theouter sleeve portion 70 that are configured to mate with correspondinginner threads defined by a connection sleeve of a hardened connector. Instill other examples, the connector fastening structure can includebayonet-type fastening structures such as bayonet grooves or bayonetslots defined either on the inside or the outside of the outer sleeveportion 70.

A fastening interface is provided for fastening the front housing piece44 to the interior sleeve portion 72 of the sleeve 26. In one example,the fastening interface includes structure for providing a snap-fitconnection. For example, as shown at FIG. 3, the interior sleeve portion72 includes retention openings 74 adapted for receiving retention tabs76 of the front housing piece 44. The retention openings 74 arepositioned on opposite sides (e.g., top and bottom sides) of theinterior sleeve portion 72. Thus, the retention openings 74 arepositioned about 180° apart from one another about a central axis of thesleeve 26.

The retention tabs 76 are provided on flexible cantilevers 78 providedat a front portion 80 of the front housing piece 44. The front portion80 of the front housing piece 44 has an outer shape that is generallycylindrical. The flexible cantilevers 78 have base ends that areunitarily formed with a cylindrical body of the front portion 80. Thefront portion 80 is configured to fit within a generally cylindricalreceptacle defined by the interior sleeve portion 72. When the frontportion 80 is fully inserted within the interior sleeve portion 72, theretention tabs 76 snap within the retention openings 74. The retentiontabs 76 can have ramp surfaces 82 that engage ramped guide notches 84defined by the interior sleeve portion 72. The ramped guide notches 84assist in guiding the retention tabs 76 to the retention openings 74.Interaction between the ramped surfaces causes the flexible cantilevers78 to flex inwardly as the front portion 80 of the front housing piece44 is inserted into the interior sleeve portion 72. When the retentiontabs 76 reach the retention openings 74, the flexible cantilevers 78elastically snap outwardly to a retaining position in which theretention tabs 76 are positioned within the retention openings 74.

The front housing piece 44 also includes an annular flange 86 having ashoulder 88 that opposes an inner end 90 of the interior sleeve portion72. Contact between the shoulder 88 and the inner end 90 prevent thefront portion 80 from being inserted too far within the interior sleeveportion 72. In this way, the shoulder 88 and the inner end 90 functionto provide a positive stop that limits the depth of insertion of thefront portion 80 into the interior sleeve portion 72.

In certain examples, the telecommunications device 20 can include akeying interface for ensuring that the front housing piece 44 isinserted into the interior sleeve portion 72 at a predefined rotationalorientation. In certain examples, the rotational orientation is takenrelative to a central longitudinal axis 92 of the subassembly 40. Incertain examples, the central longitudinal axis 92 is coaxially alignedwith a central longitudinal axis of the ferrule 52 and a centrallongitudinal axis of the sleeve 26. Thus, the central longitudinal axis92 is representative of such axes as well.

As shown at FIG. 3, an example keying arrangement includes mating partsdefined by the front portion 80 of the front housing piece 44 and theinterior sleeve portion 72 of the sleeve 26. In the depicted example,the front portion 80 defines an axial channel 94 that receives acorresponding axial rail 96 provided within the interior sleeve portion72. It will be appreciated that in other examples the axial rail 96 andthe axial channel 94 can be reversed such that the rail is provided onthe front portion 80 and the channel is provided by the interior sleeveportion 72. Furthermore, it will be appreciated that other matinginterlock configurations (e.g., flats, other projection types, etc.) canalso be used to provide rotational keying between the front housingpiece 44 and the sleeve 26.

Referring to FIGS. 2 and 5, the front portion 80 of the front housingpiece 44 also includes a flexible latching arm 98 positioned at anopposite side of the front portion 80 from the axial channel 94. Theflexible latching arm 98 extends in an axial direction and includes alatching tab 100 that extends radially toward the central longitudinalaxis 92. When the hardened connector 36 is inserted within the connectorport 28, the latching tab 100 flexes radially outwardly and then snapsto a latching position in which the latching tab 100 opposes a retainingprojection 101 that projects outwardly from a connector body of thehardened connector 36. The interior sleeve portion 72 defines an axialchannel 104 positioned opposite from the axial rail 96. The axialchannel 104 provides clearance space for allowing the flexible latchingarm 98 to flex radially outwardly as the hardened connector 36 isinitially inserted into the connector port 28 and the retainingprojection 101 moves past the latching tab 100.

Referring to FIG. 4, the front portion 80 of the front housing piece 44is generally cylindrical and is enlarged in a transverse orientationwhen compared to a rear portion 106 of the front housing piece 44. Therear portion 106 is generally rectangular in shape. Adjacent the rearend 56 of the front housing piece 44, the rear portion 106 of the fronthousing piece 44 defines oppositely positioned axial slots 108 thatdivide the rear portion 106 into oppositely positioned elastic arms 110.The elastic arms 110 define retention slots 112 configured for receivingretention tabs 114 of the rear housing piece 46. The retention slots 112and the retention tabs 114 cooperate to provide a snap-fit connectionbetween the rear housing piece 46 and the rear portion 106 of the fronthousing piece 44. The rear housing piece 46 is secured to the fronthousing piece 44 by pushing the rear housing piece forwardly into therear portion 106 of the front housing piece. As the rear housing piece46 is moved forwardly relative to the front housing piece 44, theretention tabs 144 engage the elastic arms 110 forcing the elastic armselastically apart from one another. Forward movement of the rear housingpiece 46 continues until the retention tabs 114 reach the retentionslots 112. When the retention tabs 114 reach the retention slots 112,the elastic arms 110 snap radially inwardly such that the retention tabs114 move into the retention slots 112. Front surfaces of the retentiontabs 114 can be ramped while rear surfaces are not ramped. Thisconfiguration facilitates insertion of the rear housing piece 46 intothe front housing piece 44 and resists removal of the rear housing piece46 from the front housing piece 44. It will be appreciated that the tabsand slots can be reversed and other snap-fit configurations can be usedas well.

It will be appreciated that the snap-fit connection between the rearhousing piece 46 and the front housing piece 44 is a secure snap-fitconnection that is not typically disconnected during normal use. Nostructure such as release sleeves or other similar structures areprovided for facilitating disengaging the rear housing piece 46 from thefront piece 44. While it is possible to pry the elastic arms 110 apartto remove the rear housing piece 46 from the front housing piece 44,this typically would not be done under normal conditions. Instead,snap-fit connection between the rear housing piece 46 and the fronthousing piece 44 is intended to be semi-permanent.

Referring to FIG. 4, the ferrule alignment sleeve 48 is depicted as acylindrical split-sleeve. It will be appreciated that the ferrulealignment sleeve 48 has an elastic construction that allows the ferrulealignment structure 48 to flex open to receive the front end portion 55of the ferrule 52 as well as the ferrule corresponding to the hardenedconnector 36. The ferrule alignment sleeve 48 functions to coaxiallyalign the ferrule 52 with a ferrule 53 of the hardened connector 36along the central longitudinal axis 92. In this way, an optical couplingcan be provided between the optical fibers held by the ferrules. Incertain examples, the ferrule alignment sleeve 48 can be manufactured ofa material such as Zirconia Ceramic, Phosphor Bronze, plastic materials,and other materials having suitable elastic characteristics.

It will be appreciated that the front housing piece 44 is configured toreceive and hold the ferrule alignment sleeve 48 in a position along thecentral longitudinal axis 92. For example, as best shown at FIG. 2A, thefront housing piece 44 can define a cylindrical sleeve receptacle 116for receiving the ferrule alignment sleeve 48. The front housing piece44 can also include a front stop 118 that engages a front end of theferrule alignment sleeve 48 to stop forward movement of the ferrulealignment sleeve 48 within the cylindrical sleeve receptacle 116. Theferrule alignment sleeve 116 is loaded into the sleeve receptacle 116through the rear end 56 of the front housing piece 44 and is capturedbetween the front stop 118 and the ferrule assembly 50. The fronthousing piece 44 does not include a rear stop or any other type ofpositive stopping arrangement configured for engaging a rear end of theferrule alignment sleeve 48. Instead, the ferrule assembly 50 functionsto stop rearward movement of the ferrule alignment sleeve 48 within thesleeve receptacle 116. For example, a forwardly facing stop shoulder 120provided on the ferrule hub 54 opposes and engages a rear end of theferrule alignment sleeve 48 to provide a positive stop against rearwardmovement of the ferrule alignment sleeve 48 within the sleeve receptacle116.

Referring to FIG. 5, the ferrule hub 54 includes a circumferential outerhub flange 130 defining a plurality of peripheral notches 132 spacedcircumferentially about the central longitudinal axis 92. The outer hubflange 130 includes a front side 134 and a rear side 136. When theferrule assembly 50 is loaded within the front housing piece 44, thefront side 134 of the outer flange 130 opposes a corresponding stopfeature 138 provided within the interior of the front housing piece 44.Engagement between the front side 134 of the outer flange 130 and thestop feature 138 limits forward movement of the ferrule assembly 50.When the rear housing piece 46 is snapped within the front housing piece44, a front end 140 of the rear housing piece 46 functions as a rearstop that opposes the rear side 136 of the outer flange 130. Contactbetween the rear side 136 of the outer flange 130 and the front end 140of the rear housing piece 46 limits rearward movement of the ferruleassembly 50. In this way, the ferrule assembly 50 is effectivelycaptured between the front housing piece 44 and the rear housing piece46 such that the pieces 44, 46 cooperate to retain the ferrule assembly50 in a generally fixed axial position along the central longitudinalaxis 92. In the depicted embodiment, no spring is provided for biasingthe ferrule assembly 50 in a forward direction or for allowing biasedmovement of the ferrule assembly 50 along the central longitudinal axis92. However, it will be appreciated that in other embodiments, a springmay be provided between the ferrule hub 54 and the rear housing piece 46so as to bias the ferrule assembly 50 in a forward direction.

Referring still to FIG. 5, the rear housing piece 46 can includestructure for clamping upon the ferrule hub 54 to more securely retainthe ferrule assembly 50 in a relatively fixed axial position. Forexample, the rear housing piece 46 can include resilient clamping arms142 that clamp upon a rear portion 144 of the ferrule hub 54 when thesubassembly 40 is assembled. The clamping arms 142 are positioned onopposite sides of axial slots 146 that extend rearwardly from the frontend 140 of the rear housing piece 46. The rear housing piece 46 alsodefines side windows 148 that provide a reduction in material forincreasing the flexibility of the clamping arms 142.

FIG. 9 shows an end view of a ferrule 220 holding an optical fiber 221having a fiber core 222 and a cladding 224. The cladding 224 typicallyhas a different index of refraction as compared to the fiber core 222 sothat light transmitted through the optical fiber 221 can be containedgenerally within the fiber core 222 by total internal reflection. Thefiber core 222 is not centered relative to an outer cylindrical surfaceof the ferrule 220. Rather, a fiber core axis A_(C) of the fiber core222 is offset from a central longitudinal axis A_(F) of the ferrule 220.In the example shown, the fiber core axis A_(C) is offset upwardlyrelative to the outer cylindrical surface of the ferrule 220. In otherexamples, the fiber core axis A_(C) can be offset in any other directionrelative to the outer cylindrical surface of the ferrule 220. Thedistance EC by which the fiber core axis A_(C) is offset from thecentral longitudinal axis A_(F) of the ferrule 220 corresponds to thefiber core eccentricity and is exaggerated for the purpose ofillustration. Other fiber core eccentricities can occur due to the fiberbeing offset within the opening of the ferrule, even if it is centrallylocated in the ferrule, and/or if the core is not concentric with thecladding of the fiber. The term “core offset” refers to a direction inwhich the core is offset from being perfectly concentric with theferrule. The “core offset direction” and the “direction of coreeccentricity” have the same meaning.

Due to fiber core eccentricity, signal losses within a system can occurat the connection between two optical fibers. This is because fiber coreeccentricity prevents the fiber cores of the optical fibers beingoptically coupled together from being perfectly co-axially aligned. Theworst-case scenario occurs when the ferrules of two fiber opticconnectors being coupled together have directions of core eccentricitythat are 180 degrees out of phase with respect to each other. Tominimize the negative effect of fiber core eccentricity with respect tosignal loss, it is desirable to position the directions of coreeccentricity of the ferrules of fiber optic connectors being coupledtogether in the same rotational orientation. This can be accomplished by“tuning” fiber optic connectors during manufacturing such that thedirection of core eccentricity is the same for all of the fiber opticconnectors. Tuning typically involves rotating the ferrule tointentionally position the direction of core eccentricity of the ferruleat a particular rotational orientation relative to one or more keyedcomponents of the fiber optic connector. Example tuning techniques aredisclosed at PCT Publication No. WO 02/052310 and at U.S. Pat. No.5,212,752, which are hereby incorporated by reference.

In certain examples, the front housing piece 44 can define an internaltransverse cross-sectional shape that mates with an outer transversecross-sectional shape of the ferrule hub 54 to prevent relative rotationbetween the ferrule assembly 50 and the front housing piece 44 when theinternal and outer transverse cross-sectional shapes are mated. Thistype of configuration is advantageous for allowing and/or ensuring thatthe ferrule is oriented at a particular rotational orientation about thecentral longitudinal axis 92 within the front housing piece 44. In thisway, a core offset of the ferrule can be oriented in a particularrotational orientation within the front housing piece 44 or an anglepolished of the end face of the ferrule can be oriented at a particularrotational orientation within the front housing piece 44. Orienting thecore offset in a particular orientation assists in providing tuning.Orienting the angled end face of angled polished ferrule at a particularrotational orientation ensures that mated angled polished ferrules haveend faces that oppose and are substantially parallel to one another whentheir corresponding connectors are mated together.

With regard to tuning, the core offset direction of a ferrule can bemarked on the ferrule hub 54 or elsewhere on the ferrule 52. In thisway, when the ferrule assembly 50 is loaded into the front housing piece44, a rotational position of the ferrule assembly can be selected suchthat the core offset is oriented at a predetermined rotational position.In certain examples, the mechanical interface between the ferruleassembly 50 and the interior of the front housing piece 44 can allowtwo, three, four, five or six different rotational orientations to beselected. In other examples, the core offset of the ferrule may be setat a predetermined rotational position relative to the ferrule hub, andthe ferrule hub can be rotationally keyed relative to the interior ofthe front housing piece 44 such that the ferrule hub can only beinserted into the ferrule housing piece 44 at one rotational position.In this way, because there is predetermined relationship between thecore offset and the orientation of the ferrule hub on the ferrule, thecore offset is guaranteed to be positioned at a predetermined rotationalposition about the central longitudinal axis 92 within the front housingpiece 44.

In the depicted embodiment, the interior of the front housing piece 44includes one or more teeth 149 that are received within the peripheralnotches 132 of the outer flange 130 to rotationally lock the ferruleassembly 50 in a desired rotational position. In the depicted example,six of the notches 132 are provided so the ferrule assembly 50 can bemounted in one of six possible rotational positions. During assembly,the ferrule assembly 50 is rotated to the rotational position where thecore offset is oriented at the predetermined rotational position andthen the ferrule assembly 50 is slid axially into the front housingpiece 44. As the ferrule assembly 50 is slid forwardly into the fronthousing piece 44, the teeth 149 within the front housing piece 44 matewith the notches 132 in the outer flange 130 of the ferrule hub 54 torotationally retain the ferrule assembly 50 in the preselectedrotational position.

It will be appreciated that the sleeve 26 can be referred to as a“connector port defining structure” since it functions to define theconnector port 28. In the embodiment of FIGS. 1-3, the sleeve 26 isshown unitarily integrated with the enclosure wall. In other examples,the subassembly 40 may be used with other types of connector portdefining structures that may not be integrated with a particular“enclosure wall.” For example, FIG. 8 shows the subassembly 40 matedwith a connector port defining structure 160 (see FIG. 7) mounted withinan opening 161 defined within a wall 162 of an enclosure 163. Theconnector port defining structure 160 is retained within the opening 161by a fastener 164 such as a nut having internal threads that thread oncorresponding external threads defined at the exterior of the connectorport defining structure 160. The connector port defining structure 160also includes an exterior flange 165 that opposes an outer surface ofthe wall 162. An environmental seal 170 is shown compressed between thewall 162 and the flange 165. The connector port defining structure 160includes an outer end 166 and an inner end 167. The front portion 80 ofthe front housing piece 44 of the subassembly 40 is secured to the innerend 167 by a fastening interface such as a snap-fit connection of thetype previously described herein. The outer end 166 of the connectorport defining structure 160 includes a connector fastening structure 168such as internal threads configured to mate with the fastening structure34 of the hardened connector 36. The interconnection between theconnector fastening structure 168 and the fastening structure 34 of thehardened connector 36 securely retain the hardened connector 36 withinthe connector port defining structure 160.

In one example, the fastening interface between the hardened connector36 and the connector port defining structures 26, 160 can withstand apullout force of at least 25 pounds or at least 50 pounds.

From the forgoing detailed description, it will be evident thatmodifications and variations can be made without departing from thespirit and scope of the disclosure.

PARTS LIST

-   20 telecommunications device-   22 enclosure-   24 enclosure wall-   26 sleeve-   28 connector port-   30 connector fastening structure-   32 outer end-   34 fastening structure-   36 hardened connector-   38 inner end-   40 subassembly-   42 housing-   44 front housing piece-   46 rear housing piece-   48 ferrule alignment sleeve-   50 ferrule assembly-   52 ferrule-   54 ferrule hub-   55 front end portion-   56 rear end-   58 optical fiber-   60 end wall-   62 dome-   64 environmental seal-   66 input cable-   70 outer sleeve portion-   72 interior sleeve portion-   74 retention openings-   76 retention tabs-   78 flexible cantilevers-   80 front portion-   82 ramp surfaces-   86 annular flange-   88 shoulder-   90 inner end-   92 central longitudinal axis-   94 axial channel-   96 axial rail-   98 flexible latching arm-   100 latching tab-   101 retaining projection-   102 receptacle-   104 axial channel-   106 rear portion-   108 axial slots-   110 elastic arms-   112 retention slots-   114 retention tabs-   116 sleeve receptacle-   118 front stop-   120 stop shoulder-   130 outer hub flange-   132 peripheral notches-   134 front side-   136 rear side-   138 stop feature-   140 front end-   142 clamping arms-   144 retention tabs-   144 rear portion-   148 side windows-   149 teeth-   160 connector port defining structure-   161 opening-   162 wall-   163 enclosure-   164 fastener-   165 exterior flange-   166 outer end-   167 inner end-   168 connector fastening structure-   170 environmental seal-   220 ferrule-   221 optical fiber-   222 fiber core-   224 cladding

What is claimed is:
 1. A telecommunications device comprising: anenclosure housing defining an interior volume of the enclosure andincluding: a housing piece; an enclosure wall mounted to the housingpiece; an environmental seal positioned between the housing piece andthe enclosure wall, the environmental seal providing an environmentallysealed interface between the housing piece and the enclosure wall; and aplurality of sleeves unitarily integrated with the enclosure wall, thesleeves including outer sleeve portions that project outwardly from theenclosure wall and inner sleeve portions that project inwardly from theenclosure wall into the interior volume, the sleeves defining connectorports that extend through the enclosure wall, the sleeves includingconnector fastening structures adjacent outer ends of the sleeves, theconnector fastening structures including threads defined within theouter sleeve portions and configured to mate with corresponding threadsof hardened connectors to secure the hardened connectors within theconnector ports.
 2. The telecommunications device of claim 1, includingfour of the sleeves.
 3. The telecommunications device of claim 2,wherein the sleeves are aligned in a single row.
 4. Thetelecommunications device of claim 3, further comprising an input cablereceiver projecting outwardly from the enclosure wall, the input cablereceiver being positioned offset from the single row of the sleeves. 5.The telecommunications device of claim 1, including the hardenedconnectors, wherein the hardened connectors are secured within theconnector ports.
 6. The telecommunications device of claim 5, furthercomprising subassemblies partially positioned within the interior volumeand interfaced with the hardened connectors in the connector ports. 7.The telecommunications device of claim 6, wherein the subassembliesinclude ferrule alignment sleeves and ferrules received within theferrule alignment sleeves, the ferrules supporting optical fibers thatare optically connected to optical fibers terminated by the hardenedconnectors.
 8. The telecommunications device of claim 7, wherein thesubassemblies do not include springs for allowing spring biased movementof the ferrules.
 9. The telecommunications device of claim 1, whereinthe environmental seal is a gasket.
 10. The telecommunications device ofclaim 9, wherein the gasket is positioned in a groove defined by theenclosure wall.
 11. The telecommunications device of claim 1, furthercomprising an input cable receiver projecting outwardly from theenclosure wall.
 12. The telecommunications device of claim 11, furthercomprising an input cable positioned within the input cable receiver.13. The telecommunications device of claim 1, wherein the enclosure walldefines a recessed surface, and wherein the outer sleeve portionsproject outwardly from the recessed surface.
 14. The telecommunicationsdevice of claim 1, wherein the inner sleeve portions define axialchannels at interior surfaces of the inner sleeve portions.
 15. Thetelecommunications device of claim 1, wherein outer surfaces of theouter sleeve portions are cylindrical.
 16. The telecommunications deviceof claim 1, wherein outer surfaces of the inner sleeve portions arecylindrical.
 17. The telecommunications device of claim 1, wherein thehousing piece is a dome.